Pulverizing apparatus



7 June 3, 1930. w. K. L|GG ETT PULVERIZING APPARATUS Original Filed May 11, 1925 Patented June 3, 1930 UNITED STATES PATENT OFFICE- I WILLIAM K. LIGGETT, OF COLUMBUS, OHIO, ASSIGNOR TO THE .TEFFREY MANUFAC- TURING COMPANY, OF COLUMBUS, OHIO, A CORPORATION OF OHIO able material.

PULVERIZIN G APPARATUS Application filed May 11, 1925, Serial No. 29,522. Renewed April 25, 1929.

The present invention relates to certain new and useful improvements in pulverizing apparatus, and particularly to apparatus of the class wherein material may be reduced or pulverized by contact with a plurality of radially extending beaters attached to a rotor adapted to revolve within a pulverizing chamber.

Machines of the above mentioned class are well adapted to, and are commonly used for pulverizing coal, limestone, and other fri- They may, of course, be used for reducing other materials. However, in the mining and quarrying operations whereby such materials are obtained from their native beds, tools, broken parts of machinery used in mining and quarrying operations, or bolts, nuts, and other relatively small parts accidentally detached from the cars or other equipment by which said material is handled, occasionally become mixed with the material which is fed into the machine, subjecting it to strains and shocks which sometimes break or otherwise seriously injure the machine. It has long been the practice to provide the driving pulley connection by which rotative power is applied to the rotor ofsuch a pulverizingmachine with shearing pins adapted,

by their breakage, to disconnect the rotor from its actuating force whenever said rotor is subjected to excessive load. However, due to the inertia of the rotating parts, the relief thus afforded is not always sufiicient to prevent breakage of the machine.

It is the especial object of this invention to provide in an apparatus of the class described, improved beaters adapted to be securely held in pulverizing position while contacting with the material which is. to be reduced, but which, when subjected to the strains produced by contact with unbreakable objects, will yield to the pressure thereof and thereby avoiding serious injury to the machine.

The means whereby I attain this object are fully set forth in the following specification,

and illustrated in the accompany ng drawings of which Fig. 1 is a transverse sectional view of a pulverizing machine equipped with the devices of my invention.

Referring to the drawing it will be seen' that, as here shown, my improved apparatus consists ofa reducing element which may take various forms, but in this illustration of the invention is in the form of a skeleton rotor adapted to revolve within a casing arranged to confine the material, the rotor being shown in the present instance as revolving about a horizontal axis. The casing comprises a main supporting frame 1 and a housing 2 which are joined together, as here shown, along the horizontal central plane of the rotor, although variations in this arrangement may be made. The main frame 1 has end walls and side walls preferably, though not necessarily, formed of a single casting.

At the ends of the main frame 1 are journal bearings 3 which may be of any suitable type and are designed to support the rotor element of the machine. Journaled in the bearings 3 is a shaft 4 to one end of which maybe attached a suitable pulley or other device, by

which the rotor may be connected in any suitable manner with a convenient source of rotative power. but as such devlces are well known in the art, and as they form 110 part in the present invention, their illustration and description is not thought to be required at this time. Attached to the main frame 1 in any suitable manner and extending longitudinally thereof are the grate bars 5 which form a semicylindrical floor for the reducing chamber arranged concentrically with the shaft l, and the spacing of the grate bars 5 controls the size of the maximum fragments of the product of the machine.

Mounted upon the shaft 4, and here shown in spaced relation to one another, are a plu- .rality of discs 6 which are secured to the apertures of the discs 6 are a plurality of rods 8 and 9 arranged in pairs, and upon these rods 8 and 9 are supported the heaters 10 designed to engage and reduce the material which is to be pulverized. The heaters 10 are preferably formed of castings of a refractory alloy of iron, having a relatively Y broad base portion 11, adaptedto extend between two adjacent discs, and a material engaging extension 12, the said base portion being provided with two apertures 13 and 14 so disposed that when in operative position upon the rotor the rods 8 and 9 will extend therethrough. The aperture 13 is circular in contour, adapted to snugly fit the rod 8, while the aperture 14 is elongated in an arc concentric with the aperture 13 to per mit of limited rotary movement of the beater 10 about the rod 8.

The housing 2 comprises a hopper 15 positioned directly above the rotor and adapted to receive the material which is to be pulverized, the forward wall 16 of thehopper 15 is formed of refractory-material adapted to withstand the violent contact of fragments thrown tangentially from the surface of the rotor, and at its lower end is formed a shelflike projection 17 extending into close prox imity with the path of rotation of the heater extensions 12, and this shelf constitutes an abutment adapted to intercept the advance of unpulverized fragments of material.

When the rotor revolves at sufiicient speed the centrifugal force causes the heaters 10 to rotate about their supporting rods 8 to their outermost operative position wherein the inner ends of the apertures 13 engage the rods 9, and these parts are so proportioned that under such conditions the extensions 12 6 to engage and reduce the material to be pulverized. Under ordinary operating conditions fragments of iron, or .other unpulverizahle material occasionally becomes mixed with the material fed into the hopper 15, and when such fragments of unpulverizable material engage the abutment 17 and project intojthe path of the beater extensions 13, as shown at 18' in Fig. 1, the heaters upon contacting with said obstacles, will be rotated about their pivots 8 and pass the obstruction 18 without injury to the machine, returning to their operative position immediately after passing the obstacles 18, or after the removal of said obstacles from the pulverizing chamber, thereby maintaining the perfect balance and full efficiency of the rotor.

Under some conditions of' operation it is desirable to secure the beater extensions 12 rigidly in the projected operating position. In such cases contact of the extension 12 with the unpulverizable obstacle '18 may subject the machine to violent shock, which, if the obstacle 18 is of sufiicient size, may wreck the machine. To permit the rigid attachment of the beater arms to the rotor, and at the same time protect the machine from the injurious results of shocks such as above described, I have provided the grooves 19 in the side walls of the apertures 14. and into these grooves may be fitted a relatively thin plate 20 of material of predetermined transverse strength, the parts being so proportioned and arranged that the plate 20 will engage the rod 9 and rigidly hold the beater extension 12 in operative position. It is apparent that when a heater such as last above described contacts with an unpulverizable obstacle 18 the plate 20 will be disrupted and thereby permit the rotation of the beater about its pivot, withdrawing the extension 12 into'the body of the rotor and relieving the machine from injurious shock. After passing the obstruction 18 centrifugal force will again move the extension 12 to its operative position restoring, to a considerable degree, the effective operation of the heater and maintaining balance of the rotor.

The thickness of the heater 10 is preferably such'as to completely fill the space between adjacent discs, thereby preventing the accidental removal of the breaking plate 20. After a plate 20 has been fractured in service the rod 9 may be withdrawn from the aperture 14, the beater 10 rotated outwardly a sufiicient distance to expose the grooves 19 and to permit the removal of'the fragments of the ruptured plate and the insertion of a new plate 20. The heater may then be returned to its operative position, and the rod 9 reinserted thereby againrigidly attaching the beater 10 to the rotor.

I claim 1. In a pulverizing apparatus, the combination with a rotor, a pivot carried by said rotor spaced from the axis thereof, a material engaging element mounted upon said pivot for movement thereon to and from operative position relative to said rotor, means upon said rotor to limit rotary movement of said 'material engaging element about said pivot, and means releasable by a predetermined pressure applied to said material engaging element adapted to rigidly hold said element in operative position as and for the purpose set forth. I

2. In a pulverizing apparatus, the combination with a rotor, of a pivot carried by said rotor spaced from the axis thereof, a material engaging element mounted upon said pivot, means upon the rotor to limit rotary movement of said material engaging element about said pivot, and means adapted to be broken by predetermined pressure appliedto said material engaging element to rigidly hold said element in operative position as and for the purpose set forth.

.3. In a pulverizing apparatus, the combination with a rotor, of a pivot carried by said rotor spaced from the axis thereof, a material engaging element mounted upon said pivot. means upon the rotor to limit rotary movement of said material engaging element about said pivot, and renewable means adapt ed to be broken by predetermined pressure applied to said material engaging element adapted to rigidly hold said element in operative position as and for the purpose set forth.

4. In a pulverizing apparatus, the combination with a rotor comprising two spaced apart concentric discs adapted to revolve about a central axis, of a rod carried by said discs extending parallel to and offset from said axis, a material engaging element mounted upon said rod for-rotary movement to and from operative position relative to said discs, means carried by said discs to limit the movement of said element, and means carried by said element and releasable by predetermined pressureupon said element to prevent rotary movemept of said element as and for the purpose set forth.

5. In a pulverizing apparatus, the combination with a rotor comprising two spaced apart concentric discs adapted to revolve about a central axis, of a rod carried by said discs extending parallel to and offset from said axis, a material engaging element mounted upon said rod for rotary movement relative to said discs, a second rod carried by said discs adapted to engage said material engaging element to limit its rotary moi/e ment, and devices carried by said element and releasable by predetermined pressure upon said element to prevent rotary move ment of said element as and for the purpose set forth.

6. In a pulverizing apparatus, the combination with a rotor comprising two spaced apart concentric discs adapted to revolve about a central axis, of a rod carried by said discs extending parallel to. and offset from said axis, a material engaging element mounted upon said rod for rotary movement relative to said discs, an elongated aperture in said material engaging element, a second rod carried by said discs extending through said elongated aperture and adapted to limit the rotary movement of said element, and devices carried by said element adapted to engage said rod and releasable by predetermined pressure' applied to said element to prevent rotary movement of said element as and for the purpose set forth.

7. In a pulverizing apparatus, the combination with a rotor comprising two spaced apart concentric discs adapted to revolve about a central axis, of a rod carried by said discs extending parallel to and ofiset from said axis, a material engaging element mounted upon said rod for rotary movement relative to said discs, an elongated aperture in said material engaging element, a second rod carried by said discs extending through said'elongated aperture and adapted to limit the rotary movement of said element, and a breakable member adapted to engage said second rod to prevent rotarymovement of said element as and for the purpose set forth.

8. In a pulverizing apparatus, the combination with a rotor comprising two spaced apart concentric discs adapted to revolve about acentral axis, of a rod carried by said discs extending parallel to and offset from said axis, a material engaging element mounted upon said rod for rotary movement relative to said discs, an elongated aperture in said material engaging element, a second rod carried by said discs extending through said elongated aperture and adapted to limit the rotary movement of said element, and a renewable breakable member adapted to engage said sccond rod to prevent rotary movement of said element as and for the purpose set forth. I

9. In a pulverizing apparatus, the combination with a rotor comprising two spaced apart concentric discs adapted to revolve about a central axis, of a rod carried by said discs extending parallel to and offset from said axis, a material engaging element mounted upon said rod for rotary movement relative to said dis an elongated aperture in said material engaging element, a second rod carriedby said discs extending through said elongated aperture and adapted to limit the rotary movement of said element, grooves formed in the walls of said elongated aperture, and a breakable member adapted to be inserted in said grooves and to engage said second rod to prevent rotary movement of said element as and for the purpose set forth.

10. In a beater for a pulverizing appa 'atus comprising a supporting portion and a material engaging portion, means to simport said beater for rotary n'iovement, means to limit said rotary movement, and means associated with said limiting means and releasable bya predetermined pressure applied to said material engaging portion to rigidly hold said beater in operative position.

11. In a beater for a pulverizing apparatus comprisim a supporting portion and a material engagmg portion, a plvotal hearing operative position as and for the purpose set forth.

12. In a beaterfor a pulverizing apparatus comprising a supporting portion and a material engaging portion, a bearing in said sup porting portion adapted to engage a pivotal support, an elongated aperture spaced from said pivotal support and adapted to receive a stop limiting rotary movement of said beater about said pivotal support, and means to engage said stop to rigidly hold said beater in operative position said means being releasable by predetermined pressure applied to said material engaging portion as and for the purpose set forth.

13. In a beater for a pulverizing apparatus comprising a supporting portion and a material engaging portion, a bearing in said supporting portion adapted to engagea pivotal support, an elongated aperture spaced from said pivotal support and adapted to receive a stop limiting rotary movement of said beater about said pivotal support, and a breakable member attached to said beater adapted to engage said stop to rigidly hold said beater in operative position as and for the purpose set forth.

14. In a heater for a pulverizing apparatus comprising a supporting portion and a material engaging portion,'a bearing in said supporting portion adapted to engage a pivotal support, an elongated aperture spaced from said pivotal support and adapted to receive a sto limiting rotary movement of said beater a out said pivotal support, and a renewable breakable member attached to said beater adapted to engage said stop to rigidly hold said beater in operative position as and for the purpose set forth.

15. In a beater for a pulverizing apparatus comprising a supporting portion and a material engaging portion, a bearing in said supporting portion adapted to engage a pivotal support, an elongated aperture spaced from said pivotal support and adapted to receive a stop limiting rotary movement of said beater about said pivotal support, grooves formed in the Walls of said elongated aperture, and a breakable member adapted to engage said grooves and said stop to rigidly hold said heater in operative position as and for the purpose set forth. i

16. In apparatus of the class described, the combination of a rotor, reducing means re sponsive to centrifugal action carried by said rotor, and means releasable under stress to hold said reducing means in a predetermined position.

17 In apparatus of the class described, the combination of a rotor, reducing means responsive to centrifugal action carried by said rotor, and means releasable under stress to hold said reducing means in a projected position.

18. In apparatus of the class described, the

combination of a rotor, reducing means responsive to centrifugal action carried by said rotor, means to limit movement of said reducing means in at least one direction, and means releasable understressto hold said reducing means in a predetermined position.

19. In apparatus of the class described, the combination of a rotor, reducing means responsive to centrifugalaction carried by said rotor, means to limit movement of said reducing means in both directions, and means releasable under stress to hold said reducing means in a predetermined position.

20. In apparatus of the class described, the combination of a rotor, reducing means responsive to centrifugal action carried by said rotor, means to limit movement of said reducing means in both directions, and means releasable under stress to hold said reducing means in a projected position.

21. In a pulverizing apparatus, a rotor, amultiplicitypf mutually independent beaters pivoted to said rotor in axially-extending series, the free ends of said beaters being projected beyond the periphery of said rotor upon rotation of the latter, and a member positively blocking each beater in its projected position, said members being independently yieldable under a predetermined pressure upon respective beaters to completely release the latter for inward movement.

22. In a pulverizing apparatus, a rotor, a multiplicity of mutually independent beaters pivoted to said rotor in axially-extending series, the free ends of said beaters being projected beyond the periphery of said rotor upon its rotation, abutment elements on said rotor, and abutment portions on s'aid'beaters cooperating with said elements to positively pletely release respective beaters for inward movement.

24. In a pulverizing apparatus, a rotor, a beater pivoted to said rotor, the free end of said beater being projected beyond the periphery of said rotor upon rotation of the latter, and cooperating abutment elements on said rotor and said beater for positively holding the latter in projected position, one of said elements being yieldable under a predetermined pressure to completely release said beater for inward movement.

25. Ina pulverizing apparatus, a rotor, a beater pivoted to said rotor, the free end of said beater being projected beyond the periphery of said rotor upon rotation of the latter, an abutment element on said rotor, and a renewable abutment portion on said beater cooperating with said element to positively hold said beater in projected position, said abutment portion being yieldable under a predetermined pressure to completely release said beater for inward movement.

26. In a machine of the class described, a rotor, a beater pivoted to the rotor on an axis within the peripheral outlines of the latter, said beater having a head portion remote from its axis centrifugally projected in a substantially radial direction beyond the peripheral outlines of the rotor upon rotation of the latter, and means on the rotor for limiting.

the outward movement of said-head portion, said head portion being adapted to move automatically entirely within the peripheral outlines of the rotor when the rotation of the latter is arrested.

27. In a machine of the class described, a rotor, a beater pivoted to the rotor on an axis within the peripheral outlines of the latter, said beater having a head portion remote from its axis centrifugally projected in a substantially radial direction beyond the peripheral outlines of the rotor upon rotation of the latter, means on the rotor for limiting the outward movement of said head portion, said head portion being adapted to move automatically entirely within the peripheral outlines of the rotor when the rotation of the latter is arrested, and means for limiting the inward movement of said head portion.

28. In a machine of the class .described, a rotor, a beater pivoted to the rotor on an axis within the peripheral outlines of the latter and parallel to the rotor axis, said beater having a head portion'remote from its axis projected entirely under centrifugal force in a substantially radial direction beyond the peripheral outlines of the rotor upon rotation of the latter, and means on the rotor for limiting the outward movement of said head portion, said head portion being adapted to move entirely within the peripheral outlines ofthe rotor upon the counteraction or cessation of the centrifugal force.

29. In a machine 9f the class described, a rotor, a beater pivoted to the rotor on an axis within the peripheral outlines of the latter and parallel to the rotar axis, said beater having a head portion remote from its axis projected entirely under centrifugal force in a substantially radial direction beyond the peripheral outlines of the rotor upon rotation of the latter, and means on the rotor for limiting the outward movement of said head portion, said head portion being adapted to move entirely within the peripheral outlines of the rotor upon the counteraction of cessation of the centrifugal force, and means for limiting the inward movement of said head portion.

30. In a machine of the class described, a rotor, a beater pivoted to the rotor on an axis within the peripheral outlines of the latter, said beater having a head portion remote from its axis centrifugally projected in a substantially radial direction beyond-the peripheral outlines of the rotor upon rotation of the latter, and means on the rotor for limiting the outward movement of said head portion, said head portion being adapted to move automatically entirely within the petion of the latter is arrested, said head portion having a working face rearwardly and outwardly inclined relative to a radial plane of the rotor when the head portion is in pro jected position. V

31. In a machine of the class described, a rotor comprising a number of co-axially disposed substantially circular plates, a series of beaters pivoted between adjacent ones of said plates on an axis within the peripheral outlines of the plates and parallel to the rotor axis, each of said heaters having a head portion remote from its axis centrifugally projected in a substantially radial direction beyond the peripheral outlines of said plates upon rotor rotation, and abutment means on the rotor for limiting the outward movement of said head portions, said head portions being adapted to move automatically entirely within the peripheral outlines of the rotor upon the counter-action or cessation of the centrifugal force.

32. In a machine of the class described, a

rotor comprising a number of co-axially disbeing adapted to move automatically en-.

tirely within the peripheral outlines of the rotor upon the counter-action or cessation of the centrifugal force, each of said head portions having a working face rearwardly and outwardly inclined relative to a radial plane of the rotor when the head portion is in projected position.

33. In a machine of the class described, a rotor, a beater pivoted to the rotor on an axis within the peripheral outlines of the latter, said beater having a head portion remote from its axis centrifugally projected in parallel to the rotor axis and passing through 7 my hand.

outward and a substantially radial direction beyond the peripheral outlines of the rotor upon rotation of the latter and automatically movable entirely within said peripheral outlines upon counter-action or cessation of the centrifugal force, and abutment means'on the rotor, said beater having a pair of abutment faces (:0 operable with said abutment means to limit inward movement of said beater.

34. In a machine of the class described, a

rotor, a beater pivoted to the rotor on an.

axis within the peripheral outlines of the latter, said beater having a head portion remote from its axis centrifugally projected in a substantially radial direction beyond the peripheral outlines of the rotor upon rotation of the latter and automatically movable entirely within said peripheral outlines upon counter-action or cessation oi the centrifugal force, and abutment means on the rotor, said beater having a pair of abutment faces cooperable with said abutment means to limit outward and inward movement of said beated and a working face rearwardly and outwardly inclined relative to a radial plane of the rotor when the head portion isv in projected position.

35. In a machine of the class described, a rotor comprising a number of co-axially dis-- posed substantially circular plates, a rod said plates entirely within their peripheral outlines, a series of beater-s pivoted on said rod between adjacent ones of said plates, each of said beaters having a head portion remote from said ,rod projected in a substantially radial direction beyond the peripheral outlines of said plates upon rotor rotation and automatically movable entirely within said peripheral outlines upon countor-action or cessation of the centrifugal force, and a second rod supported between said plates parallel to the first, each of said boaters having a pair of-abutment faces'cooperable'with said second rod to limit outward and inward beater movement.

In testimony whereof I have hereunto set WILLIAM K. Lienrr. 

